Pilot design for Multi-Cell MU-MIMO-OFDM with beamforming

Multi-Cell Multi-User MIMO-OFDM system with a set of tri-sector base stations serves multiple mobile users. A sophisticated PACE design needs to trade off the attainable channel estimation accuracy with the induced losses in bandwidth and power efficiency. MIMO transmission, transmit beamforming, spatial multiplexing, Multi-Cell interference further complicate pilot design. In this paper a unified analytical framework is developed to evaluate the performance at the receiver for the downlink of a Multi-Cell Multi-User MIMO-OFDM system employing fixed transmit beamforming and affected by neighbors interference. The performance in terms of MSE, SINR and attainable spectral efficiency are evaluated for different pilot types. The numerical results highlight the impact of the Multi-Cell interference in terms of trade off between the achievable system capacity, the accuracy of channel estimates and pilot overhead.